U.S. patent application number 17/694389 was filed with the patent office on 2022-06-23 for low profile prosthetic mitral valve.
The applicant listed for this patent is Neovasc Tiara Inc.. Invention is credited to Ephraim Ben-Abraham, Eric Soun-Sang Fung, Karen Tsoek-Ji Wong.
Application Number | 20220192826 17/694389 |
Document ID | / |
Family ID | 1000006193378 |
Filed Date | 2022-06-23 |
United States Patent
Application |
20220192826 |
Kind Code |
A1 |
Fung; Eric Soun-Sang ; et
al. |
June 23, 2022 |
LOW PROFILE PROSTHETIC MITRAL VALVE
Abstract
A low-profile prosthetic valve for treating a native valve
includes a radially expandable frame having an expanded
configuration and a collapsed configuration. The atrial end of the
prosthetic valve forms a flared shape that engages an atrial
surface of the native valve. The flare shape flares downward toward
a ventricle of the native valve when initially expanded followed by
inversion of the flared shape to form a tapered shape tapering
toward the ventricle and flaring toward the atrium of the native
valve when fully expanded. The prosthetic valve also has a
plurality of prosthetic valve leaflets that open and close to
control fluid flow through the prosthetic valve.
Inventors: |
Fung; Eric Soun-Sang;
(Vancouver, CA) ; Wong; Karen Tsoek-Ji; (Richmond,
CA) ; Ben-Abraham; Ephraim; (Rochester, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Neovasc Tiara Inc. |
Richmond |
|
CA |
|
|
Family ID: |
1000006193378 |
Appl. No.: |
17/694389 |
Filed: |
March 14, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16906782 |
Jun 19, 2020 |
11311376 |
|
|
17694389 |
|
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62864008 |
Jun 20, 2019 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2/243 20130101;
A61F 2/2418 20130101; A61F 2250/0039 20130101; A61F 2230/0067
20130101; A61F 2220/0008 20130101; A61F 2230/0054 20130101; A61F
2/2409 20130101 |
International
Class: |
A61F 2/24 20060101
A61F002/24 |
Claims
1. A low-profile prosthetic valve for treating a native valve in a
patient, said valve comprising: a radially expandable frame having
an expanded configuration, a collapsed configuration, an atrial end
and a ventricular end, wherein in the collapsed configuration the
expandable frame is sized and shaped for minimally invasive
delivery to the native valve, wherein in the expanded configuration
the expandable frame is configured to engage the native valve,
wherein the atrial end forms a flared shape in the expanded
configuration, and configured to engage an atrial surface of the
native valve, wherein the flared shape flares downward toward a
ventricle of the native valve when initially expanded followed by
inversion of the flared shape to form a tapered shape tapering
toward the ventricle and flaring toward an atrium of the native
valve when fully expanded; and a plurality of prosthetic valve
leaflets having a free end and an opposite end coupled to an inner
portion of the expandable frame, an open configuration and closed
configuration, wherein the open configuration the free ends of the
plurality of prosthetic valve leaflets are disposed away from one
another relative thereby forming an aperture through which fluid
flows in an antegrade direction, and wherein in the closed
configuration the free ends are disposed closer together than in
the open configuration thereby substantially closing the aperture
and preventing the fluid from flowing therethrough in a retrograde
direction.
2. The prosthetic valve of claim 1, further comprising a plurality
of commissure posts each having a free end and an opposite end, the
opposite end coupled to the expandable frame, the free end facing
the ventricle when the expandable frame is in the expanded
configuration, and wherein the plurality of prosthetic valve
leaflets are coupled to the plurality of commissure posts.
3. The prosthetic valve of claim 2, wherein the free end comprises
a plurality of apertures extending therethrough, the plurality of
apertures sized to receive a suture filament that secures the
plurality of prosthetic valve leaflets to the plurality of
commissure posts.
4. The prosthetic valve of claim 2, wherein the plurality of
commissure posts each have a locking tab coupled to the free end,
the locking tab configured to releasably couple the prosthetic
valve with a delivery catheter.
5. The prosthetic valve of claim 1, further comprising a plurality
of ventricular anchors coupled to the ventricular end of the
expandable frame, the ventricular anchors extending radially
outward from the expandable frame in the expanded configuration,
and configured to engage a ventricular side of the native
valve.
6. The prosthetic valve of claim 5, wherein at least one of the
plurality of ventricular anchors and at least one of the plurality
of commissure posts are disposed in a common closed cell in the
expandable frame that is bounded by a plurality of struts.
7. The prosthetic valve of claim 5, wherein the plurality of
ventricular anchors each comprise a locking tab coupled to an
inferior portion of the ventricular anchor, the locking tab on the
ventricular anchor configured to releasably couple the prosthetic
valve with a delivery catheter.
8. The prosthetic valve of claim 5, wherein the plurality of
ventricular anchors comprise an anterior ventricular anchor
configured to engage a fibrous trigone on an anterior portion of a
native mitral valve in the native heart, and a posterior
ventricular anchor configured to engage a posterior portion of an
annulus of the mitral valve or a posterior ventricular portion of
the native valve.
9. The prosthetic valve of claim 5, wherein the plurality of
ventricular anchors comprise a cover element disposed over at least
two struts coupled to the expandable frame.
10. The prosthetic valve of claim 5, wherein the plurality of
ventricular anchors comprise a V-shaped strut coupled to the
expandable frame, wherein an apex of the V-shaped strut is
configured to engage tissue, the prosthetic valve further
comprising a cover element disposed over the V-shaped strut.
11. The prosthetic valve of claim 1, wherein the expandable frame
comprises a plurality of annular rings coupled together to form a
paraboloidal shape.
12. The prosthetic valve of claim 11, wherein the plurality of
annular rings comprises a plurality of concentric rings having
decreasing diameter coupled together.
13. The prosthetic valve of claim 11, wherein adjacent annular
rings are coupled together to form a plurality of closed cells
extending circumferentially around the expandable frame.
14. The prosthetic valve of claim 1, further comprising a plurality
of ventricular wings on the ventricular end, wherein the plurality
of ventricular wings has an expanded configuration and a collapsed
configuration, wherein in the collapsed configuration the plurality
of ventricular wings is substantially parallel with a longitudinal
axis of the prosthetic valve, and wherein the expanded
configuration the plurality of ventricular wings extends radially
outward from the longitudinal axis to form a flange configured to
engage a ventricular surface of the native valve.
15. A low-profile prosthetic valve system for treating a native
valve in a patient, said system comprising: the prosthetic valve of
claim 1; and a delivery catheter releasably coupled to the
prosthetic valve, the delivery catheter configured to deliver the
prosthetic valve to the native valve.
16. The system of claim 15, wherein the delivery catheter comprises
a locking element for releasably engaging the prosthetic valve.
Description
CLAIM OF PRIORITY
[0001] The present application is a division of U.S.
Non-Provisional patent application Ser. No. 16/906,782 (Attorney
Docket No. 5131.019US1) filed on Jun. 19, 2020 and claims the
benefit of U.S. Provisional Patent Application No. 62/864,008
(Attorney Docket No. 5131.019PRV) filed on Jun. 20, 2019; the
entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] Mitral valve regurgitation, also known as mitral
incompetence, is a serious cardiac condition where the mitral valve
fails to properly close and prevent retrograde blood flow across
the native mitral valve. This condition can compromise cardiac
function and can be debilitating or life threatening.
[0003] Current treatments for mitral insufficiency include
traditional surgical repair of the native valve. Less invasive
transcatheter treatments are being developed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] In the drawings, which are not necessarily drawn to scale,
like numerals may describe similar components in different views.
Like numerals having different letter suffixes may represent
different instances of similar components. The drawings illustrate
generally, by way of example, but not by way of limitation, various
embodiments discussed in the present document.
[0005] FIG. 1 is a schematic illustration of the left ventricle of
a heart showing blood flow during systole.
[0006] FIG. 2 is a schematic illustration of the left ventricle of
a heart having prolapsed leaflets in the mitral valve.
[0007] FIG. 3A is a schematic illustration of a heart in a patient
suffering from cardiomyopathy where the heart is dilated, and the
leaflets do not meet.
[0008] FIG. 3B shows, normal closure of the leaflets.
[0009] FIG. 3C shows abnormal closure in the dilated heart.
[0010] FIG. 4 illustrates mitral valve regurgitation in the left
ventricle of a heart having impaired papillary muscles.
[0011] FIGS. 5A-5B illustrate the anatomy of the mitral valve.
[0012] FIG. 6A shows a top view of an example of a low-profile
prosthetic valve.
[0013] FIG. 6B shows the ventricular anchors of the example in FIG.
6A.
[0014] FIG. 6C shows a cover that may be attached to the
ventricular anchors of the valve in FIG. 6A
[0015] FIG. 6D shows a perspective view of the valve in FIG.
6A.
[0016] FIG. 7A shows a top view of another example of a low-profile
prosthetic valve.
[0017] FIG. 7B shows the ventricular anchors of the example in FIG.
7A.
[0018] FIG. 7C shows an example of a cover that may be used on the
ventricular anchors of FIG. 7B.
[0019] FIG. 7D shows a perspective view of the example in FIG.
7A.
[0020] FIG. 8A shows a top view of another example of a low-profile
prosthetic valve.
[0021] FIG. 8B shows the prosthetic valve of FIG. 8A in a partially
deployed configuration.
[0022] FIG. 8C shows the prosthetic valve of FIG. 8A in a fully
deployed configuration.
[0023] FIG. 8D shows the prosthetic valve of FIG. 8A disposed in a
native mitral valve.
[0024] FIG. 9A-9F show a delivery catheter that is releasably
coupled to a prosthetic valve.
[0025] FIGS. 10A-10C show a locking mechanism for releasably
coupling a prosthetic valve with a delivery catheter.
[0026] FIG. 11 shows a side view of a locking mechanism for
releasably coupling a prosthetic valve with a delivery
catheter.
[0027] FIGS. 12A-12B show a locking mechanism for releasably
coupling a prosthetic valve with a delivery catheter.
[0028] FIGS. 13A-13D illustrate an example of a method for
deploying a prosthetic valve in a native valve.
[0029] FIG. 14 shows an example of a prosthetic valve in a native
valve.
[0030] FIGS. 15A-15D show another example of a method for deploying
a prosthetic valve in a native valve.
DETAILED DESCRIPTION
[0031] Traditional surgical repair of the mitral valve can be an
effective treatment but requires open heart surgery, a long
hospitalization and recovery period. Less invasive transcatheter
treatments are being developed and are promising but can be
challenging to implant and many have not received regulatory
approval for commercial distribution. Therefore, there is a need
for improved devices to treat mitral insufficiency. At least some
of these challenges are addressed by the examples disclosed
herein.
[0032] While the examples disclosed herein are directed to an
implantable prosthetic mitral valve for treating mitral
regurgitation, one of skill in the art will appreciate that this is
not intended to be limiting, and the device and methods disclosed
herein may also be used to treat other cardiac valves such as the
tricuspid valve, aortic valve, pulmonary valve, etc., as well as
other valves in the body such as venous valves or any anatomical
structure which is used to control the flow of fluids or other
materials.
[0033] Cardiac Anatomy.
[0034] The left ventricle LV of a normal heart H in systole is
illustrated in FIG. 1. The left ventricle LV is contracting and
blood flows outwardly through the aortic valve AV, a tricuspid
valve in the direction of the arrows. Back flow of blood or
"regurgitation" through the mitral valve MV is prevented since the
mitral valve is configured as a "check valve" which prevents back
flow when pressure in the left ventricle is higher than that in the
left atrium LA. The mitral valve MV comprises a pair of leaflets
having free edges FE which meet evenly to close, as illustrated in
FIG. 1. The opposite ends of the leaflets LF are attached to the
surrounding heart structure along an annular region referred to as
the annulus AN. The free edges FE of the leaflets LF are secured to
the lower portions of the left ventricle LV through chordae
tendineae CT (also referred to herein as the chordae) which include
a plurality of branching tendons secured over the lower surfaces of
each of the valve leaflets LF. The chordae CT in turn, are attached
to the papillary muscles PM which extend upwardly from the lower
portions of the left ventricle and interventricular septum IVS.
[0035] Referring now to FIGS. 2-4, a number of structural defects
in the heart can cause mitral prolapse since inadequate tension is
transmitted to the leaflet via the chordae. While the other leaflet
LF1 maintains a normal profile, the two valve leaflets do not
properly meet and leakage from the left ventricle LV into the left
atrium LA will occur, as shown by the arrow.
[0036] Regurgitation also occurs in the patients suffering from
cardiomyopathy where the heart is dilated and the increased size
prevents the valve leaflets LF from meeting properly, as shown in
FIG. 3A. The enlargement of the heart causes the mitral annulus to
become enlarged, making it impossible for the free edges FE to meet
during systole. The free edges of the anterior and posterior
leaflets normally meet along a line of coaptation C as shown in
FIG. 3B, but a significant gap G can be left in patients suffering
from cardiomyopathy, as shown in FIG. 3C.
[0037] Mitral valve regurgitation can also occur in patients who
have suffered ischemic heart disease where the functioning of the
papillary muscles PM is impaired, as illustrated in FIG. 4. As the
left ventricle LV contracts during systole, the papillary muscles
PM do not contract sufficiently to effect proper closure. The
leaflets LF1 and LF2 then prolapse, as illustrated. Leakage again
occurs from the left ventricle LV to the left atrium LA, as shown
by the arrow.
[0038] FIG. 5A more clearly illustrates the anatomy of a mitral
valve MV which is a bicuspid valve having an anterior side ANT and
a posterior side POST. The valve includes an anterior (aortic)
leaflet AL and a posterior (mural) leaflet PL. Chordae tendineae CT
couple the valve leaflets AL, PL with the antero-lateral papillary
muscle ALPM and the postero-medial papillary muscle PMPM. The valve
leaflets AL, PL join one another along a line referred to as the
antero-lateral commissure ALC and the posterior-medial commissure
PMC. The annulus AN circumscribes the valve leaflets, and two
regions adjacent an anterior portion of the annulus, on opposite
sides of the anterior leaflet are referred to as the left fibrous
trigone LFT and also the right fibrous trigone RFT. These areas are
indicted by generally by the solid triangles. FIG. 5B more clearly
illustrates the left and right fibrous trigones, LFT, RFT.
[0039] Prosthetic Valve
[0040] Prosthetic valves have been surgically implanted in the
heart as a treatment for mitral regurgitation. Some of these valves
have been valves harvested from animals such as porcine valves, and
others have been prosthetic mechanical valves with or without a
tissue covering. More recently, minimally invasive catheter
technology has been used to deliver prosthetic valves to the heart.
These valves typically include an anchor for securing the
prosthetic valve to the patient's heart, and a valve mechanism
coupled to the anchor. The valve mechanism often is either a
mechanical valve, a valve with animal tissue, or combinations
thereof. The prosthetic valve once implanted, takes over for the
malfunctioning native valve, thereby reducing or eliminating valvar
insufficiency. Some of these valves are challenging to deliver and
some are difficult to accurately anchor. Others are large in size
which can obstruct the chambers of the heart. While some of these
valves appear promising, there still is a need for improved valves
that address at least some of these challenges. The following
specification discloses examples of a prosthetic valve, a delivery
system for the prosthetic valve, and methods of delivering the
valve that may overcome some of the challenges associated with
existing prosthetic valves.
[0041] FIG. 6A illustrates an example of a low profile prosthetic
mitral valve 600 shown in a flat cut view. The prosthetic mitral
valve 600 is an expandable frame formed from a plurality of
interconnected struts and may be cut from a flat sheet of material
such as stainless steel, nitinol or other biocompatible materials.
It may be balloon expandable or self-expanding. The expandable
frame is in a flat planar configuration after cutting from the
sheet of material and may be heat treated and shape set into a
desired shape as will be discussed below. The flat pattern includes
a plurality of concentric annular rings 602, 604 that are formed
from a plurality of struts which extend around the circumference of
the prosthesis. Rings are smaller in diameter and circumference as
they get closer to the center of the prosthetic valve. Thus ring
602 has a larger diameter and larger circumference than ring 604.
Adjacent rings are coupled together with a plurality of radially
extending struts 612 to form a plurality of closed cells
circumferentially disposed around the prosthetic valve with
adjacent closed cells sharing at least one common strut. Each ring
602, 604 may include a plurality of circumferentially oriented
struts that all have the same geometry. For example, outer-most
ring 602 incudes a plurality of wishbone shaped struts coupled
together to form the annular ring. The wishbone shaped struts may
all be the same in ring 602 and they may include two oppositely
sloped struts that are coupled together with an arcuate strut that
forms a protuberance or peak in the wishbone shaped strut at the
inflection point between the two oppositely sloped struts.
[0042] The next adjacent ring 604 disposed radially inward from
ring 602 is similarly formed with a plurality of wishbone shaped
struts coupled together. The wishbone shaped struts in ring 604 may
all be the same in ring 604 and they may be similarly formed from
two oppositely sloped struts that are coupled together with an
arcuate strut that forms a protuberance or peak in the wishbone
shaped strut at the inflection point between the two oppositely
sloped struts. The sizes and angles of the struts in ring 604 may
be different than ring 602 since the two rings are concentric with
one another and therefore ring 604 has a smaller diameter and
circumference than outer ring 602. A plurality of linear struts 612
that extend radially outward from the center of the prosthesis
couple rings 602 and 604 together to form closed cells 610. The
closed cells 610 formed between ring 602 and 604 may all have the
same geometry, or they may vary.
[0043] Struts may be wishbone shaped in order to divert stress and
strain away from the apex of the wishbone thereby allowing a
greater angular range of motion to be achieved for a given maximum
strain, or allowing a lower maximum strain to occur for the same
given range of motion.
[0044] A Y-shaped strut 616 is coupled to the wishbone shaped
second ring 604 with the tail of the Y extending radially inward
toward the center of the prosthesis, thereby forming a lemon shaped
closed cell with a peak and valley on opposite sides of the closed
cell, and pointed ends on the two other sides of the closed cell.
The tails of the Y may be coupled together to define a central
aperture 618 in the prosthesis. In this example, the central
aperture 618 is star shaped with three pointed arms extending
radially outward to form the star shape.
[0045] A plurality of inner closed cells 620, here three closed
cells 620, are formed by two V-shaped struts 622 on opposite sides
of the closed cell 620 coupled to the tails of adjacent Y-shaped
struts 616 to form the closed cells 620. Each closed cell 620
contains a commissure tab 606 and two ventricular anchor struts
614
[0046] Commissure tabs 606 may be adjacent the center of the
prosthesis and may include a plurality of suture holes so that the
prosthetic valve leaflets may be sutured to the commissure tabs.
The commissure tabs 606 may be a rectangular shaped strut with a
slit through the middle for receiving prosthetic leaflets. In this
example there are three prosthetic valve leaflets (not shown)
attached to the commissure tabs forming a tricuspid prosthetic
valve. The prosthetic valve leaflets are not illustrated for ease
in viewing the expandable frame. The commissure tabs are disposed
in between struts 614 which form ventricular anchor tabs that
anchor the prosthesis to a ventricular portion of the native valve,
such as an anterior portion of the native valve (such as the
fibrous trigones) and a posterior portion of the native valve.
Struts 614 form part of the ventricular anchors. Two struts 614 are
disposed on either side of the commissure tabs 606. One end of
strut 614 is coupled to a tail of the Y-shaped strut 616, and the
opposite end of struts 614 is a free end that may be bend radially
outward. The free end may include a through hole which is used for
attachment of a cover (not shown). The cover may be any material
such as a polymer like Dacron, and forms a foot which is a soft
atraumatic tip for engaging tissue. The Dacron or other polymer
cover material provides greater surface area and therefore reduces
the chance of the ventricular anchor tabs piercing tissue. The
ventricular tabs can then angulate away from the valve frame during
expansion to allow anchoring on the fibrous trigones or any other
anterior portion of the ventricular side of the native valve, or
any portion on the posterior annulus of the native valve.
[0047] Facing radially inward toward the center of the device may
be a plurality of anchor tabs 608, here mushroom head shaped tabs
608 or T-shaped heads, which allow the prosthesis to be coupled to
a delivery catheter as will be described below. In this or any
other example, the T-shaped or mushroom head anchor tabs may be
omitted and simply have an aperture through the tab that allows a
pin or other connector element to be disposed in the aperture for
releasable coupling with a delivery catheter, as will be described
in greater detail below. The anchor tabs 608 are disposed on a
portion of strut that joins two tails of Y-shaped struts 616
together. Thus, in this example there are three connection points
that may be made with a delivery catheter.
[0048] FIG. 6B illustrates prosthetic valve 600 with the cover 624
disposed over the struts 614 and prosthetic frame to form a foot
which helps create the ventricular anchors. This is shown by the
shaded regions. The foot includes an enlarged head region and a
narrower body. Again, the enlarged head provides a larger surface
area and therefore minimizes pressure applied to tissue during
anchoring in order to eliminate or reduce tissue trauma. Other
aspects of FIG. 6B are the same as FIG. 6A.
[0049] FIG. 6C shows an example of a cover 624 that may be attached
to struts 614 to form the atraumatic tip of the ventricular
anchors. The cover may be Dacron, or another polymer, or any
material that has the desired mechanical properties. Cover 624 has
an enlarged head region and a thinner elongate body region. The
enlarged head region provided greater surface area in order to
reduce contact pressure with tissue during anchoring in order to
eliminate or reduce tissue piercing and trauma.
[0050] FIG. 6D is a perspective view of the prosthetic valve 600
shown in FIGS. 6A-6B but with the covering 630 shown disposed over
the expandable frame and after shape setting. In addition to a
covering disposed over the ventricular anchors 614 to form
atraumatic anchor tabs, the same material or another material may
be disposed over any or all of the struts and closed cells to
minimize perivalvular leakage and promote tissue ingrowth. FIG. 6D
shows the prosthetic valve 600 in the fully expanded configuration
after shape setting, where the prosthesis is flared upward in an
atrial direction (or tapered in a ventricular direction) and the
upper atrial end which is the inflow end of the prosthesis is the
largest diameter and the valve tapers down to a smaller diameter on
the ventricular end which is the outflow end. The funnel shape of
the frame may also be described as parabaloidal-like with the
concave portion of the paraboloid facing up toward the atrium and
the convex portion of the paraboloid facing downward toward the
ventricle. The prosthetic valve has an intermediate expanded
configuration where the paraboloid is inverted so that the
prosthesis flares outward from the upper to lower ends so the
flaring is in the direction of the ventricle or the tapering is in
the direction of the atrium. If parabaloid shaped, then and the
concave portion of the paraboloid faces downward toward the
ventricle while the convex portion of the paraboloid faces upward
toward the atrium. This intermediate expanded configuration is
illustrated and described in greater detail below. Prosthetic valve
600 also includes three commissure posts with three prosthetic
valve leaflets 632 coupled to the commissure posts to form the
prosthetic valve mechanism.
[0051] FIG. 7A illustrates an example of a low profile prosthetic
mitral valve 700 shown in a flat cut view. The prosthetic mitral
valve 700 is an expandable frame formed from a plurality of
interconnected struts and may be cut from a flat sheet of material
such as stainless steel, nitinol or other biocompatible materials.
It may be balloon expandable or self-expanding. The expandable
frame is in a flat planar configuration after cutting from the
sheet of material and may be heat treated and shape set into a
desired shape as will be discussed below. The flat pattern includes
a plurality of concentric annular rings 702, 704 that are formed
from a plurality of struts which extend around the circumference of
the prosthesis. Rings are smaller in diameter and circumference as
they get closer to the center of the prosthetic valve. Thus ring
702 has a larger diameter and larger circumference than ring 704.
Adjacent rings are coupled together with a plurality of radially
extending struts 712 to form a plurality of closed cells
circumferentially disposed around the prosthetic valve with
adjacent closed cells sharing at least one common strut. Each ring
702, 704 may include a plurality of circumferentially oriented
struts that all have the same geometry. For example, outer-most
ring 702 incudes a plurality of wishbone shaped struts coupled
together to form the annular ring. The wishbone shaped struts may
all be the same in ring 702 and they may include two oppositely
sloped struts that are coupled together with an arcuate strut that
forms a protuberance or peak in the wishbone shaped strut at the
inflection point between the two oppositely sloped struts.
[0052] The next adjacent ring 704 disposed radially inward from
ring 702 is similarly formed with a plurality of wishbone shaped
struts coupled together. The wishbone shaped struts in ring 704 may
all be the same in ring 704 and they may be similarly formed from
two oppositely sloped struts that are coupled together with an
arcuate strut that forms a protuberance or peak in the wishbone
shaped strut at the inflection point between the two oppositely
sloped struts. The sizes and angles of the struts in ring 704 may
be different than ring 702 since the two rings are concentric with
one another and therefore ring 704 has a smaller diameter and
circumference than outer ring 702. A plurality of linear struts 712
that extend radially outward from the center of the prosthesis
couple rings 702 and 704 together to form closed cells 710. The
closed cells 710 formed between ring 702 and 704 may all have the
same geometry, or they may vary. The construct of the connected
struts making rings coupled together to form closed cells creates a
lattice structure that once shape set provides a flower-like shape,
for example similar to a daisy.
[0053] Struts may be wishbone shaped in order to divert stress and
strain away from the apex of the wishbone thereby allowing a
greater angular range of motion to be achieved for a given maximum
strain, or allowing a lower maximum strain to occur for the same
given range of motion.
[0054] A Y-shaped strut 716 is coupled to the wishbone shaped
second ring 704 with the tail of the Y extending radially inward
toward the center of the prosthesis, thereby forming several tear
drop shaped closed cells with pointed ends on opposite sides of the
tear drop shape as well as several lemon shaped closed cells which
are substantially the same as in the example FIG. 6A. The tails of
the Y may be coupled together with V-shaped struts to define an
inner closed cell 720 with a central aperture 718 in the
prosthesis. In this example, the central aperture 718 has a central
circular hole with a plurality of pointed arms extending radially
outward from the central circular hole.
[0055] Inner closed cell 720 is formed by V-shaped struts 722
coupled to the tails of adjacent Y-shaped struts 716 to form the
closed cell 720. Closed cell 720 contains three commissure tabs 706
and extending radially outward from closed cell 720 are three
V-shaped struts which form ventricular anchors 724 configured to
engage a ventricular inferior surface of the native valve. The legs
of the ventricular anchors may be coupled to the tails of the
Y-shaped struts, and the apex of the V (or the trough of the V, or
free end of the V) may include a hole extending therethrough sized
to receive a suture so that a cover similar to the cover in FIG. 6C
may be attached to the anchor to form an atraumatic tip.
[0056] Commissure tabs 706 may be adjacent the center of the
prosthesis and may include a plurality of suture holes so that the
prosthetic valve leaflets may be sutured to the commissure tabs.
The commissure tabs 706 may be a rectangular shaped strut with a
slit through the middle for receiving prosthetic leaflets. In this
example there are three prosthetic valve leaflets (not shown)
attached to the commissure tabs forming a tricuspid prosthetic
valve. The prosthetic valve leaflets are not illustrated for ease
in viewing the expandable frame. The commissure tabs are disposed
in between adjacent ventricular anchors 724 that anchor the
prosthesis to a ventricular portion of the native valve, such as an
anterior portion of the native valve (such as the fibrous trigones)
and a posterior portion of the native valve. The free end of the
ventricular anchor may be bend radially outward. The free end may
include a through hole which is used for attachment of a cover (not
shown). The cover may be any material such as a polymer like
Dacron, and forms a foot which is a soft atraumatic tip for
engaging tissue. The Dacron or other polymer cover material
provides greater surface area and therefore reduces the chance of
the ventricular anchor tabs piercing tissue. The ventricular tabs
can then angulate away from the valve frame during expansion to
allow anchoring on the fibrous trigones or any other anterior
portion of the ventricular side of the native valve, or any portion
on the posterior annulus of the native valve.
[0057] Facing radially inward toward the center of the device may
be a plurality of anchor tabs 708 coupled to the commissures 706,
here mushroom head shaped tabs 708 or T-shaped heads, which allow
the prosthesis to be coupled to a delivery catheter as will be
described below. In addition to the three anchor tabs 708 on the
commissures, three additional anchor tabs 726 are coupled to a
strut that joins the tails of two adjacent Y-shaped struts 716 and
anchor tabs 726 face radially inward toward the center of the
prosthesis. Anchor tabs 726 may also be mushroom head shaped, or
T-shaped, or other shapes. Both anchor tabs 708, 726 may be used to
releasably couple the prosthesis with a delivery catheter. Thus, in
this example there are six connection points that may be made with
a delivery catheter. Other aspects of the example in FIG. 7A may be
substantially similar to the example in FIG. 6A.
[0058] FIG. 7B illustrates prosthetic valve 700 with the cover 730
disposed over the ventricular anchors 714 and prosthetic frame to
form a foot which helps create the ventricular anchors. The foot
includes an enlarged head region and a narrower body. Again, the
enlarged head provides a larger surface area and therefore
minimizes pressure applied to tissue during anchoring in order to
eliminate or reduce tissue trauma. Other aspects of FIG. 7B are the
same as FIG. 7A.
[0059] FIG. 7C shows an example of a cover 730 that may be attached
to ventricular anchors 714 to form the atraumatic tip of the
ventricular anchors. The cover may be Dacron, or another polymer,
or any material that has the desired mechanical properties. Cover
730 has an enlarged head region and a thinner elongate body region.
The enlarged head region provides greater surface area in order to
reduce contact pressure with tissue during anchoring in order to
eliminate or reduce tissue piercing and trauma.
[0060] FIG. 7D is a perspective view of the prosthetic valve 700
shown in FIGS. 7A-7B but with the covering removed for ease in
viewing the struts of the expandable frame, and after shape
setting. In addition to a covering disposed over the ventricular
anchors, the same material or another material may be disposed over
the any or all of the struts and closed cells. FIG. 7D shows the
prosthetic valve 700 in the fully expanded configuration after
shape setting, where the prosthesis flares in the atrial direction
(or tapers toward the ventricle) and the upper atrial end which is
the inflow end of the prosthesis is the largest diameter and the
valve tapers down to a smaller diameter on the ventricular end
which is the outflow end. The funnel shape of the frame may also be
described as parabaloidal-like with the concave portion of the
paraboloid facing up toward the atrium and the convex portion of
the paraboloid facing downward toward the ventricle. The prosthetic
valve has an intermediate expanded configuration where the
prosthesis is tapered toward the atrium or flared toward the
ventricle, and if paraboloid shaped, the paraboloid is inverted so
that the prosthesis flares outward from the upper end to the lower
end and the concave portion of the paraboloid faces downward toward
the ventricle while the convex portion of the paraboloid faces
upward toward the atrium. This intermediate expanded configuration
is illustrated and described in greater detail below.
[0061] FIG. 8A illustrates another example of a low profile
prosthetic mitral valve 800 shown in a flat cut view. Prosthetic
valve 800 is substantially similar to the prosthetic valve 600 in
FIGS. 6A-6D with the major difference being the addition of
ventricular petals or wings 830 to help anchor the prosthesis to
the ventricular side of the native valve and capture adjacent
native valve leaflets. The prosthetic mitral valve 800 is an
expandable frame formed from a plurality of interconnected struts
and may be cut from a flat sheet of material such as stainless
steel, nitinol or other biocompatible materials. It may be balloon
expandable or self-expanding. The expandable frame is in a flat
planar configuration after cutting from the sheet of material and
may be heat treated and shape set into a desired shape as will be
discussed below. The flat pattern includes a plurality of
concentric annular rings 802, 804 that are formed from a plurality
of struts which extend around the circumference of the prosthesis.
Rings are smaller in diameter and circumference as they get closer
to the center of the prosthetic valve. Thus ring 802 has a larger
diameter and larger circumference than ring 804. Adjacent rings are
coupled together with a plurality of radially extending struts 812
to form a plurality of closed cells circumferentially disposed
around the prosthetic valve with adjacent closed cells sharing at
least one common strut. Each ring 802, 804 may include a plurality
of circumferentially oriented struts that all have the same
geometry. For example, outer-most ring 802 includes a plurality of
wishbone shaped struts coupled together to form the annular ring.
The wishbone shaped struts may all be the same in ring 802 and they
may include two oppositely sloped struts that are coupled together
with an arcuate strut that forms a protuberance or peak in the
wishbone shaped strut at the inflection point between the two
oppositely sloped struts.
[0062] The next adjacent ring 804 disposed radially inward from
ring 802 is similarly formed with a plurality of wishbone shaped
struts coupled together. The wishbone shaped struts in ring 804 may
all be the same in ring 804 and they may be similarly formed from
two oppositely sloped struts that are coupled together with an
arcuate strut that forms a protuberance or peak in the wishbone
shaped strut at the inflection point between the two oppositely
sloped struts. The sizes and angles of the struts in ring 804 may
be different than ring 802 since the two rings are concentric with
one another and therefore ring 804 has a smaller diameter and
circumference than outer ring 802. A plurality of linear struts 812
that extend radially outward from the center of the prosthesis
couple rings 802 and 804 together to form closed cells 810. The
closed cells 810 formed between ring 802 and 804 may all have the
same geometry, or they may vary.
[0063] Struts may be wishbone shaped in order to divert stress and
strain away from the apex of the wishbone thereby allowing a
greater angular range of motion to be achieved for a given maximum
strain, or allowing a lower maximum strain to occur for the same
given range of motion.
[0064] A Y-shaped strut 816 is coupled to the wishbone shaped
second ring 804 with the tail of the Y extending radially inward
toward the center of the prosthesis, thereby forming a lemon shaped
closed cell with a peak and valley on opposite sides of the closed
cell, and pointed ends on the two other sides of the closed cell.
The Y-shaped strut may also be coupled to the wishbone shaped
second ring 804 with the tail of the Y extending radially inward
toward the center of the prosthesis to form several tear drop
shaped closed cells with pointed ends on opposite side of the tear
drop shape. The tails of the Y may be coupled together to define a
central aperture 818 in the prosthesis. In this example, the
central aperture 818 is star shaped with three pointed arms
extending radially outward to form the star shape.
[0065] A plurality of inner closed cells 820, here three closed
cells 820, are formed by two V-shaped struts 822 on opposite sides
of the closed cell 820 coupled to the tails of adjacent Y-shaped
struts 816 to form the closed cells 820. Each closed cell 820
contains a commissure tab 806 and two ventricular anchor struts
814.
[0066] Commissure tabs 806 may be adjacent the center of the
prosthesis and may include a plurality of suture holes so that the
prosthetic valve leaflets may be sutured to the commissure tabs.
The commissure tabs 806 may be a rectangular shaped strut with a
slit through the middle for receiving prosthetic leaflets. In this
example there are three prosthetic valve leaflets (not shown)
attached to the commissure tabs forming a tricuspid prosthetic
valve. The prosthetic valve leaflets are not illustrated for ease
in viewing the expandable frame. The commissure tabs are disposed
in between struts 814 which form ventricular anchor tabs that
anchor the prosthesis to a ventricular portion of the native valve,
such as an anterior portion of the native valve (such as the
fibrous trigones) and a posterior portion of the native valve.
Struts 814 form part of the ventricular anchors. Two struts 814 are
disposed on either side of the commissure tabs 806. One end of
strut 814 is coupled to a tail of the Y-shaped strut 816, and the
opposite end of struts 814 is a free end that may be bent radially
outward. The free end may include a through hole which is used for
attachment of a cover (not shown) such as suturing. The cover may
be any material such as a polymer like Dacron, and forms a foot
which is a soft atraumatic tip for engaging tissue. The Dacron or
other polymer cover material provides greater surface area and
therefore reduces the chance of the ventricular anchor tabs
piercing tissue. The ventricular tabs can then angulate away from
the valve frame during expansion to allow anchoring on the fibrous
trigones or any other anterior portion of the ventricular side of
the native valve, or any portion on the posterior annulus of the
native valve. The ventricular anchors may also help capture the
native valve leaflets between the ventricular anchor and an outer
surface of the expandable frame. If the prosthetic valve has
ventricular wings or petals (as described below), the native valve
leaflets may also be captured by the wings or petals and this may
help keep the native valve leaflets out of the flow path. There may
be any number of ventricular anchors, but in this example, there
are three.
[0067] Facing radially inward toward the center of the device may
be a plurality of anchor tabs 808, here mushroom head shaped tabs
or T-shaped heads, which allow the prosthesis to be coupled to a
delivery catheter as will be described below. The anchor tabs 808
are disposed on a portion of strut that joins two tails of Y-shaped
struts 816 together. Thus, in this example there are three
connection points that may be made with a delivery catheter.
[0068] Prosthetic valve 800 also includes arcuate struts 830 which
have opposed ends which slope in opposite directions and a curved
connector at the inflection point. Here, there are three arcuate
struts 830 and each end of the arcuate struts is coupled to the
arms of a Y-shaped strut 818 to form petals or wings. The petals or
wings form a second ventricular anchor on the ventricular side of
the prosthesis as well helping to capture native valve leaflets.
The petals or wings may extend downward away from the prosthesis
toward the ventricle during delivery and initial deployment and
then the petals or wings extend radially outward and away from the
anchor in the fully expanded configuration to form a flange
circumferentially disposed around the expandable frame that can
engage a ventricular portion of the native valve just below the
annulus so that the annulus is captured between the petals or
wings, and the upper rings. The upper atrial flared region and the
lower ventricular wings or petals therefore provide upper and lower
shoulders that may act as a clamp that can capture or sandwich the
native valve annulus therebetween, providing good purchase of the
tissue for anchoring the prosthesis into the native anatomy.
Additionally, the ventricular wings or petals also may help capture
the native valve leaflets and move them out of the flow passage to
ensure optimal valve function. Here, three struts 830 are shown but
any number may be used. The ventricular anchors 814 are
substantially the same as previously described in FIG. 6A and may
be used in conjunction with the petals or wings to further help
secure the prosthetic valve to the native valve.
[0069] FIG. 8B illustrates prosthetic valve 800 of FIG. 8A after
shape setting and in a partially deployed configuration where the
atrial end has expanded into a conical shape with the atrial
diameter increasing toward the ventricle to form the cone or flared
region. The expanded configuration may be a paraboloid with a
concave portion facing downward toward the ventricle, but still
disposed above the valve annulus 850. A delivery catheter is not
shown for convenience. The petals or wings 830 extend axially
downward from the expandable frame and pass through the native
valve orifice through the annulus 850. The petals or wings 830
extend substantially parallel with the longitudinal axis of the
prosthesis in this partially deployed configuration. A cover (not
shown) similar to cover 624 in FIG. 6B may be disposed over the
struts 814 and any or all portions of the prosthetic frame to form
a foot which helps create the ventricular anchors. The foot may
include an enlarged head region and a narrower body. Again, the
enlarged head provides a larger surface area and therefore
minimizes pressure applied to tissue during anchoring in order to
eliminate or reduce tissue trauma. Other aspects of FIG. 8B are the
same as FIG. 8A.
[0070] FIG. 8C shows the prosthetic valve 800 of FIG. 8B in the
fully deployed configuration where the atrial cone has been
inverted to now form a paraboloid with the concave portion facing
upward toward the atrium but above the annulus 850. The cone can
then fit into the native valve and the walls of flared cone prevent
the valve from slipping through the native valve orifice. Also, the
petals or wings 830 have now radially expanded outward so they are
orthogonal or otherwise transverse to the longitudinal axis of the
prosthesis to form a flange that can be anchored against a lower
surface of the native valve on the ventricular side. Additionally,
the prosthetic valve also has ventricular anchors and they are
shown extending radially outward to engage with the underside of
the annulus, for example on the fibrous trigones on the anterior
side of the native valve or on a posterior portion of the native
valve. Again, a cover like cover 624 in FIG. 6B may be disposed
over the ventricular anchors 814 to form the atraumatic tip of the
ventricular anchors. The cover may be Dacron, or another polymer,
or any material that has the desired mechanical properties. The
cover may have an enlarged head region and a thinner elongate body
region. The enlarged head region provided greater surface area in
order to reduce contact pressure with tissue during anchoring in
order to eliminate or reduce tissue piercing and trauma.
[0071] FIG. 8D shows the prosthetic valve 800 from FIG. 8A fully
deployed in a native mitral valve MV. When fully deployed the
larger diameter portion of the flare rests in the left atrium LA
and prevents the prosthesis from migrating into the left ventricle
LV. Ventricular anchor tabs 814 may include two anterior anchor
tabs for anchoring on the fibrous trigones on an anterior portion
of the native valve and a posterior anchor tab which anchors on a
posterior portion such as a posterior shelf of the native valve.
Ventricular wings 830 or petals are also disposed on the
ventricular side to further help with anchoring on a ventricular
side of the native valve. FIG. 8D is shown with the cover 860 such
as Dacron or another polymer, fabric, or tissue coupled to the
expandable frame. Prosthetic leaflets 862 are shown attached to the
commissure posts. Anchor tabs 808 on the commissure posts are used
to releasably couple the prosthesis with a delivery catheter. Here,
there are three anchor tabs.
[0072] Releasable Coupling with a Delivery Catheter
[0073] FIGS. 9A-9F illustrate a delivery catheter which may be used
to carry any of the prosthetic valves disclosed herein. The
delivery catheter may be releasably coupled to the prosthesis so
that once the prosthesis has been correctly positioned and
deployed, the prosthetic valve is released from the delivery
catheter and left in place while the delivery system is removed
from the patient.
[0074] FIG. 9A shows the outer surface of a delivery catheter 900
which includes an outer sheath 902 and a tapered atraumatic distal
tip 904. The tapered atraumatic distal tip 904 may be removed
before the prosthetic valve is inserted and expanded.
[0075] FIG. 9B shows that outer sheath 902 is generally tubular
shaft with a single lumen 906 extending through the shaft. The
lumen 906 is configured to house any of the prosthetic valves
disclosed herein and provide a constraint that keeps the prosthetic
valve in the collapsed configuration during delivery.
[0076] FIG. 9C shows the prosthesis 908 schematically disposed in
lumen 906 of outer sheath 902. Prosthesis 908 may be any of the
prosthetic valves disclosed herein, and is constrained in a
collapsed configuration.
[0077] FIG. 9D shows proximal retraction of outer sheath 902
removes a constraint from prosthesis 908 and allows the prosthesis
to partially self-expand but the sheath still is disposed over the
portion of the prosthesis that is releasably engaged with the
delivery catheter and this provides a constraint that prevents the
prosthesis from inverting and fully expanding. Here, only the
portions of the prosthesis which are releasably coupled to the
delivery catheter are illustrated. The rest of the prosthetic valve
has been omitted from FIGS. 9D-9F for convenience. As outer sheath
906 is retracted proximally, the prosthesis self-expands to form
the partially deployed prosthesis where a paraboloid is formed with
a concave portion facing downward toward the ventricle of the
patient's heart. Therefore, an inverted cone shape is formed with
the small end of the cone facing toward the atrium and the large
end of the cone facing downward toward the ventricle. Only the arms
of the prosthesis with the connector tabs remain coupled to the
delivery catheter. Examples of tabs include the mushroom head
shaped tabs or T-shaped tabs previously described above. The
prosthesis remains in the atrium above the native valve at this
stage of delivery and expansion.
[0078] FIG. 9E shows that further proximal retraction of outer
sheath 902 (or distal advancement of an intermediate shaft 910
disposed in the lumen 906 of outer sheath 902 allows the prosthetic
valve to continue to open up and invert so that the paraboloid
faces the opposite direction with the concave portion of the
paraboloid facing toward the atrium. The prosthetic valve 908
remains coupled to the delivery catheter 900.
[0079] FIG. 9F shows release of the prosthetic valve 908 from the
delivery catheter 900 once the prosthetic valve has been correctly
positioned and expanded into the native valve. Here, an inner shaft
912 is slidably disposed in a lumen of intermediate shaft 910. As
inner shaft 912 is advanced distally a disc or cap 914 is moved
away from a hub coupled to the intermediate shaft 910. The hub
includes slots 916 which capture the mushroom head or T-shaped head
of the prosthesis. So, as the cap 914 moves away from the hub and
slots 914, the mushroom head or T-shaped head becomes unconstrained
and is free to self-expand out of the slot 914. Once out of the
slot, the prosthesis 908 is then detached from the delivery
catheter 900. Further details on the coupling mechanism are
described below.
[0080] In the example of FIGS. 9A-9F, there are only 3 connections
between the prosthetic valve and the delivery catheter. Additional
connection points may be used such as by adding tabs on the
ventricular anchors as seen in FIG. 7A so that there are six
connection points. Any number of connection points may be used an
any combination of connectors on the commissure or on the
ventricular anchors may be used. Moreover, in this example or any
example where there are multiple releasable connections between the
prosthesis and the delivery catheter, the connections may all be
released simultaneously, individually one after another in serial
fashion and independently of one another, or in desired groupings,
or in stages.
[0081] FIGS. 10A-10C show another example of a coupling mechanism
that may be used to releasably couple a prosthetic valve with the
delivery system. This example is similar to that shown in FIGS.
9A-9F with the major difference being that the slotted region on
the hub and the disc or cap are reversed. The outer sheath is
omitted from FIGS. 10A-10C for convenience.
[0082] In FIG. 10A the delivery catheter includes an inner shaft
1006 and an intermediate shaft 1004 slidably disposed over inner
shaft 1006. Prosthetic valve 1002 is releasably coupled to the
delivery catheter. Again, only the portions of prosthetic valve
coupled to the delivery catheter are shown. The prosthetic valve
1002 may be any of the prosthetic valves disclosed herein. Also, in
this view, the prosthesis is partially deployed and expanded to
form the paraboloid with the concave portion facing downward toward
the ventricle. The paraboloid also may be described as an inverted
cone with the small end of the cone facing toward the atrium and
the large end of the cone facing downward toward the ventricle.
[0083] In FIG. 10B further retraction of an outer sheath (not
shown) allows the prosthesis to continue to expand and invert so
that the prosthesis forms a cone with the larger diameter end
facing toward the atrium and the smaller diameter end facing toward
the ventricle. A hub 1008 with slots 1010 is coupled to the inner
shaft 1006. The slots 1010 are sized to receive the T-shaped heads
or mushroom heads on the prosthesis and hold them when the disc or
cap 1012 is apposed with the hub 1008. Disc or cap 1012 is coupled
to intermediate shaft 1004.
[0084] In FIG. 10C distal advancement of inner shaft 1006 moves hub
1008 away from cap or disc 1012 exposing slots 1010 and allowing
the mushroom head or T-shaped heads of the prosthesis to release
from the delivery catheter. Or intermediate shaft 1004 may be
retracted proximally to separate the disc or cap from the hub, or a
combination of proximal retraction of intermediate shaft 1004 and
distal advancement inner shaft 1006 may be used to separate the two
and release the prosthetic valve from the delivery catheter.
[0085] In the example of FIGS. 10A-10C, there are only 3
connections between the prosthetic valve and the delivery catheter.
Additional connection points may be used such as by adding tabs on
the ventricular anchors as seen in FIG. 7A so that there are six
connection points. Any number of connection points may be used an
any combination of connectors on the commissure or on the
ventricular anchors may be used.
[0086] FIG. 11 shows a side view of the releasable connection
between a prosthetic valve and a delivery catheter and highlights
an example of a locking mechanism that allows the prosthetic valve
to be releasably coupled with the delivery catheter.
[0087] The delivery catheter 1100 includes an outer sheath 1102
slidably disposed over an intermediate shaft 1104 which is slidably
disposed over an inner shaft 1106. All three shafts may move
proximally or distally relative to one another. The outer sheath
1102 includes a lumen that houses a prosthetic valve 1116. The
prosthetic valve 1116 may be any of the prosthetic valves disclosed
herein. This figure only shows the portions of the prosthetic valve
that are releasably coupled to the delivery catheter. The rest of
the valve has been omitted for convenience. A hub 1108 with slots
1110 is coupled to the intermediate shaft. A cap or disc 1112 is
coupled to the inner shaft 1106. Tabs 1114 such as mushroom heads
or T-shaped heads may fit in the slots 1110 in the hub and when the
cap 1112 is apposed with the hub, the tabs 1114 are captured and
thus the prosthetic valve is coupled to the delivery catheter. Once
the prosthetic valve is fully deployed and positioned, the inner
shaft 1106 may be moved relative to the intermediate shaft 1104 so
the cap is moved away from the hub, thereby allowing the tabs 1114
to release from the slots 1110 and decouple the prosthetic valve
from the delivery catheter.
[0088] FIGS. 12A-12B illustrate another example of a locking
mechanism for releasably coupling a prosthetic valve with a
delivery catheter.
[0089] FIG. 12A shows delivery catheter 1200 which includes an
outer sheath (not illustrated) for housing the prosthetic valve, an
intermediate shaft 1202 slidably disposed in the outer sheath, and
an inner shaft 1210 slidably disposed in the intermediate shaft
1202. A cap 1206 is coupled to the intermediate shaft 1202 and a
hub 1208 has pins 1212 extending proximally from the hub and
parallel with the longitudinal axis of the delivery catheter 1200.
Here, only the arms or portions of the prosthetic valve 1204 that
are releasably coupled with the delivery catheter are shown. The
prosthetic valve 1204 may be any of the examples disclosed herein,
and includes tabs 1214 with an aperture through the tip of the tab.
The pins 1212 may be disposed in the apertures to releasably couple
the prosthetic valve with the delivery catheter when the cap is
apposed with the pins.
[0090] FIG. 12B shows release of the prosthetic valve 1204 from the
delivery catheter 1200. Here, intermediate shaft 1202 is retracted
proximally or inner shaft 1210 is advanced distally, or a
combination of both proximal and distal motion of shafts 1202, 1210
move the cap 1206 away from the pins 1212 allowing the apertures
1214 in the connector tabs on the prosthetic valve 1204 to slide
off the pins thereby decoupling the prosthetic valve from the
delivery catheter.
[0091] In any of the examples of locking mechanisms for coupling
and decoupling the prosthesis from the delivery catheter, it may be
desirable to recapture the prosthetic valve. This may be
accomplished any time up until the prosthetic valve is released
from the delivery catheter. Thus, if the prosthesis requires
repositioning or for some other reason the physician decides not to
implant the prosthesis, the operator may allow the prosthesis to
return to its unbiased shape of being concave facing downstream and
the prosthesis may be resheathed and constrained in its collapsed
configuration. Once it is repositioned or a decision is made to
deploy the prosthesis, the deployment procedure may be
recommenced.
Delivery Method
[0092] FIGS. 13A-13D illustrate an example of a method of
delivering a prosthetic valve to a mitral valve in a patient.
[0093] In FIG. 13A, a sheath 1302 is introduced into the patient's
heart using techniques known in the art such as percutaneously
through a vein in the groin or via a cutdown, and over a guidewire.
The sheath 1302 is advanced transseptally across the septal wall
from the right atrium RA to the left atrium LA. A delivery catheter
1304 carrying a prosthetic valve 1306 such as any of the prosthetic
valves described herein, is advanced through the sheath 1302 into
the left atrium. The distal tip of the delivery catheter is
positioned or steered so that it is adjacent the native mitral
valve MV. The sheath may be proximally retracted or the delivery
catheter advanced distally past the sheath to partially expose the
prosthetic valve 1306.
[0094] FIG. 13B the sheath is removed from the prosthetic valve
1306 thereby removing a constraint and allowing the prosthetic
valve 1306 to expand into an intermediate configuration. The
intermediate configuration is a cone shape or paraboloid with the
concave surface facing downward toward the ventricle. The small
diameter portion of the cone is facing the left atrium and the
larger diameter portion of the cone faces the ventricle. The
prosthetic valve is still coupled to the delivery catheter and
disposed in the left atrium LA above the mitral valve MV.
[0095] In FIG. 13C further expansion of the prosthetic valve 1306
and optionally with distal pressure applied to the prosthesis
against the mitral valve MV, the prosthesis 1306 inverts so that
the cone now has its large diameter portion facing the left atrium
LA and the smaller diameter portion faces toward the left ventricle
LV. The cone may be a paraboloid shape with the concave portion
facing toward the left atrium LA and the convex portion facing
toward the left ventricle. The ventricular anchor tabs also expand
radially outward to engage a ventricular portion of the native
valve. For example, the prosthetic valve may have two anterior
ventricular anchors 1308 that engage the fibrous trigones on the
anterior portion of the native mitral valve and a posterior
ventricular anchor 1310 that engages a posterior portion of the
native valve on the ventricular side. If the posterior portion has
an annular posterior shelf region, the posterior ventricular anchor
may land there.
[0096] In FIG. 13D the prosthetic valve 1306 is fully deployed and
anchored into the native valve and the delivery catheter and sheath
have been removed from the patient.
[0097] FIG. 14 shows a prosthetic valve 1402 disposed in a native
mitral valve MV. When fully deployed the larger diameter portion of
the cone rests in the left atrium LA and prevents the prosthesis
from migrating into the left ventricle. Ventricular anchor tabs may
include two anterior anchor tabs 1406 for anchoring on the fibrous
trigones on an anterior portion of the native valve and a posterior
anchor tab 1404 which anchors on a posterior portion such as a
posterior shelf of the native valve. FIG. 14 is shown without a
cover and without the prosthetic leaflets in order to show the
struts of the ventricular anchor tabs 1404, 1406 and the commissure
tabs 1408. In this example all three ventricular anchors and all
three commissure tabs include anchor tabs for releasable coupling
with a delivery catheter such as those previously described.
[0098] FIGS. 15A-15D illustrate another example of deployment of a
prosthetic valve such as the example in FIGS. 8A-8C.
[0099] In FIG. 15A, a sheath 1502 is introduced into the patient's
heart using techniques known in the art such as percutaneously
through a vein in the groin or via a cutdown, and over a guidewire.
The sheath 1502 is advanced transseptally across the septal wall
from the right atrium RA to the left atrium LA. A delivery catheter
1504 carrying a prosthetic valve 1506 such as the valve in FIGS.
8A-8C is advanced through the sheath 1502 into the left atrium. The
distal tip of the delivery catheter is positioned or steered so
that it is adjacent the native mitral valve MV. The sheath may be
proximally retracted, or the delivery catheter advanced distally
past the sheath to partially expose the prosthetic valve 1506.
[0100] FIG. 15B the sheath is removed from the prosthetic valve
1506 thereby removing a constraint and allowing the prosthetic
valve 1506 to expand into an intermediate configuration. The
intermediate configuration is a cone shape or paraboloid with the
concave surface facing downward toward the ventricle. The small
diameter portion of the cone is facing the left atrium and the
larger diameter portion of the cone faces the ventricle. The
prosthetic valve is still coupled to the delivery catheter and
disposed in the left atrium LA above the mitral valve MV. Wings or
petals 1508 extend axially downward from prosthetic valve 1506 and
may be substantially parallel with the longitudinal axis of the
prosthetic valve. The wings or petals pass through the orifice of
the native valve.
[0101] In FIG. 15C further expansion of the prosthetic valve 1506
and optionally with distal pressure applied to the prosthesis
against the mitral valve MV, the prosthesis 1506 inverts so that
the cone now has its large diameter portion facing the left atrium
LA and the smaller diameter portion faces toward the left ventricle
LV. The cone may be a paraboloid shape with the concave portion
facing toward the left atrium LA and the convex portion facing
toward the left ventricle. The ventricular anchor tabs if present,
also expand radially outward to engage a ventricular portion of the
native valve. For example, the prosthetic valve may have two
anterior ventricular anchors that engage the fibrous trigones on
the anterior portion of the native mitral valve and a posterior
ventricular anchor that engages a posterior portion of the native
valve on the ventricular side. If the posterior portion has an
annular posterior shelf region, the posterior ventricular anchor
may land there. The wings or petals 1508 expand radially outward so
they are perpendicular or otherwise transverse to the longitudinal
axis of the prosthesis to form a lower flange that can engage the
bottom of the mitral valve on the ventricular surface to further
anchor the device and also to help capture the native leaflets.
[0102] In FIG. 15D the prosthetic valve 1506 is fully deployed and
anchored into the native valve and the delivery catheter and sheath
have been removed from the patient.
Covering
[0103] Many of the figures illustrate only the expandable
prosthetic valve frame without the prosthetic valve leaflets
attached and also without a cover attached to the frame. However,
as discussed above, a cover such as tissue, a polymer or fabric may
be applied to the ventricular anchors to help form a foot that can
engage tissue in the native valve without piercing or causing
trauma to the tissue.
[0104] Additionally, in any of the examples disclosed herein, a
cover may be applied to all of the frame or portions of the frame.
The cover may be a fabric such as Dacron, or tissue such as
pericardial tissue, or any other biocompatible material. The cover
may be applied to the frame to prevent perivalvar leakage around
the frame, as well as promoting tissue ingrowth to help further
anchor and secure the prosthesis to the native anatomy. For
example, the cover may be applied to the conical flange that rests
against the atrial floor, or it may be applied to the ventricular
flange that rests against the ventricular portion of the annulus,
or the cover may be applied to both. The entire frame maybe
covered, or only portions covered.
[0105] Also, as discussed, the examples generally do not illustrate
the prosthetic valve leaflets attached to the prosthetic valve
frame for convenience. However, prosthetic valve leaflets are known
in the art and commonly two or three prosthetic leaflets may be
applied to the frame to form either a bicuspid or tricuspid
prosthetic valve. Of course, any number of leaflets may be used
such as a single prosthetic leaflet, or four leaflets or more than
four leaflets. The prosthetic valve leaflets may be tissue such as
pericardial tissue, or they me fabric, a polymer, or other
materials known in the art.
NOTES AND EXAMPLES
[0106] The following, non-limiting examples, detail certain aspects
of the present subject matter to solve the challenges and provide
the benefits discussed herein, among others.
[0107] In Example 1 a low-profile prosthetic valve for treating a
native valve in a patient comprises: a radially expandable frame
having an expanded configuration, a collapsed configuration, an
atrial end and a ventricular end, wherein in the collapsed
configuration the expandable frame is sized and shaped for
minimally invasive delivery to the native valve, wherein in the
expanded configuration the expandable frame is configured to engage
the native valve, wherein the atrial end forms a flared shape in
the expanded configuration, and is configured to engage an atrial
surface of the native valve, wherein the flared shape flares
downward toward a ventricle of the native valve when initially
expanded followed by inversion of the flared shape to form a
tapered shape tapering toward the ventricle and flaring toward an
atrium of the native valve when fully expanded; and a plurality of
prosthetic valve leaflets having a free end and an opposite end
coupled to an inner portion of the expandable frame, an open
configuration and closed configuration, wherein the open
configuration the free ends of the plurality of prosthetic valve
leaflets are disposed away from one another relative thereby
forming an aperture through which fluid flows in an antegrade
direction, and wherein in the closed configuration the free ends
are disposed closer together than in the open configuration thereby
substantially closing the aperture and preventing the fluid from
flowing therethrough in a retrograde direction.
[0108] Example 2 is the prosthetic valve of Example 1, further
comprising a plurality of commissure posts each having a free end
and an opposite end, the opposite end coupled to the expandable
frame, the free end facing the ventricle when the expandable frame
is in the expanded configuration, and wherein the plurality of
prosthetic valve leaflets are coupled to the plurality of
commissure posts.
[0109] Example 3 is the prosthetic valve of any of Examples 1-2,
wherein the free end comprises a plurality of apertures extending
therethrough, the plurality of apertures sized to receive a suture
filament that secures the plurality of prosthetic valve leaflets to
the plurality of commissure posts.
[0110] Example 4 is the prosthetic valve of any of Examples 1-3,
wherein the plurality of commissure posts each have a locking tab
coupled to the free end, the locking tab configured to releasably
couple the prosthetic valve with a delivery catheter.
[0111] Example 5 is the prosthetic valve of any of Examples 1-4,
further comprising a plurality of ventricular anchors coupled to
the ventricular end of the expandable frame, the ventricular
anchors extending radially outward from the expandable frame in the
expanded configuration, and configured to engage a ventricular side
of the native valve.
[0112] Example 6 is the prosthetic valve of any of Examples 1-5,
wherein at least one of the plurality of ventricular anchors and at
least one of the plurality of commissure posts are disposed in a
common closed cell in the expandable frame that is bounded by a
plurality of struts.
[0113] Example 7 is the prosthetic valve of any of Examples 1-6,
wherein the plurality of ventricular anchors each comprise a
locking tab coupled to an inferior portion of the ventricular
anchor, the locking tab on the ventricular anchor configured to
releasably couple the prosthetic valve with a delivery
catheter.
[0114] Example 8 is the prosthetic valve of any of Examples 1-7,
wherein the plurality of ventricular anchors comprise an anterior
ventricular anchor configured to engage a fibrous trigone on an
anterior portion of a native mitral valve in the native heart, and
a posterior ventricular anchor configured to engage a posterior
portion of an annulus of the mitral valve or a posterior
ventricular portion of the native valve.
[0115] Example 9 is the prosthetic valve of any of Examples 1-8,
wherein the plurality of ventricular anchors comprise a cover
element disposed over at least two struts coupled to the expandable
frame.
[0116] Example 10 is the prosthetic valve of any of Examples 1-9,
wherein the plurality of ventricular anchors comprise a V-shaped
strut coupled to the expandable frame, wherein an apex of the
V-shaped strut is configured to engage tissue, the prosthetic valve
further comprising a cover element disposed over the V-shaped
strut.
[0117] Example 11 is the prosthetic valve of any of Examples 1-10,
wherein the expandable frame comprises a plurality of annular rings
coupled together to form a paraboloidal shape.
[0118] Example 12 is the prosthetic valve of any of Examples 1-11,
wherein the plurality of annular rings comprises a plurality of
concentric rings having decreasing diameter coupled together.
[0119] Example 13 is the prosthetic valve of any of Examples 1-12,
wherein adjacent annular rings are coupled together to form a
plurality of closed cells extending circumferentially around the
expandable frame.
[0120] Example 14 is the prosthetic valve of any of Examples 1-13,
further comprising a plurality of ventricular wings on the
ventricular end, wherein the plurality of ventricular wings has an
expanded configuration and a collapsed configuration, wherein in
the collapsed configuration the plurality of ventricular wings are
substantially parallel with a longitudinal axis of the prosthetic
valve, and wherein the expanded configuration the plurality of
ventricular wings extend radially outward from the longitudinal
axis to form a flange configured to engage a ventricular surface of
the native valve.
[0121] Example 15 is a low-profile prosthetic valve system for
treating a native valve in a patient, said system comprising: the
prosthetic valve of any of Examples 1-14; and a delivery catheter
releasably coupled to the prosthetic valve, the delivery catheter
configured to deliver the prosthetic valve to the native valve.
[0122] Example 16 is the system of Example 15, wherein the delivery
catheter comprises a locking element for releasably engaging the
prosthetic valve.
[0123] Example 17 is a method for delivering a prosthetic valve to
a native valve in a heart of a patient, said method comprising:
providing a delivery catheter carrying the prosthetic valve;
positioning the prosthetic valve adjacent the native valve;
partially deploying the prosthetic valve so the prosthetic valve
forms a flared shape disposed above the native valve and flaring
toward a ventricle of the heart; inverting the flared shape so the
initial flared shape becomes a tapered shape disposed above the
native valve and tapering toward the ventricle; radially expanding
a plurality of ventricular anchors or ventricular wings on a
ventricular end of the prosthetic valve to engage a ventricular
surface of the native valve; and releasing the prosthetic valve
from the delivery catheter.
[0124] Example 18 is the method of Example 17, wherein radially
expanding the plurality of ventricular anchors or ventricular wings
comprises anchoring at least some of the plurality of ventricular
anchors on a fibrous trigone of the native valve or a posterior
ventricular portion of the native valve.
[0125] Example 19 is the method of any of Examples 17-18, wherein
radially expanding the plurality of ventricular anchors or
ventricular wings comprises radially expanding a plurality of
ventricular wings from a position substantially parallel with a
longitudinal axis of the prosthetic valve to a position extending
radially outward from the longitudinal axis, and engaging the
plurality of ventricular wings with a ventricular surface of the
native valve.
[0126] Example 20 is the method of any of Examples 17-19, further
comprising reducing or eliminating regurgitation across the
prosthetic valve.
[0127] Example 21 is the method of any of Examples 17-20, wherein
the native valve is a mitral valve.
[0128] Example 22 is the method of any of Examples 17-21, wherein
releasing the prosthetic valve from the delivery catheter comprises
disengaging a plurality of commissure posts on the prosthetic valve
from the delivery catheter.
[0129] Example 23 is the method of any of Examples 17-22, wherein
releasing the prosthetic valve from the delivery catheter comprises
disengaging a plurality of locking tabs on the plurality of
ventricular anchors from the delivery catheter.
[0130] In Example 24, the apparatuses or methods of any one or any
combination of Examples 1-23 can optionally be configured such that
all elements or options recited are available to use or select
from.
[0131] The above detailed description includes references to the
accompanying drawings, which form a part of the detailed
description. The drawings show, by way of illustration, specific
embodiments in which the invention can be practiced. These
embodiments are also referred to herein as "examples." Such
examples can include elements in addition to those shown or
described. However, the present inventors also contemplate examples
in which only those elements shown or described are provided.
Moreover, the present inventors also contemplate examples using any
combination or permutation of those elements shown or described (or
one or more aspects thereof), either with respect to a particular
example (or one or more aspects thereof), or with respect to other
examples (or one or more aspects thereof) shown or described
herein.
[0132] In the event of inconsistent usages between this document
and any documents so incorporated by reference, the usage in this
document controls.
[0133] In this document, the terms "a" or "an" are used, as is
common in patent documents, to include one or more than one,
independent of any other instances or usages of "at least one" or
"one or more." In this document, the term "or" is used to refer to
a nonexclusive or, such that "A or B" includes "A but not B," "B
but not A," and "A and B," unless otherwise indicated. In this
document, the terms "including" and "in which" are used as the
plain-English equivalents of the respective terms "comprising" and
"wherein." Also, in the following claims, the terms "including" and
"comprising" are open-ended, that is, a system, device, article,
composition, formulation, or process that includes elements in
addition to those listed after such a term in a claim are still
deemed to fall within the scope of that claim. Moreover, in the
following claims, the terms "first," "second," and "third," etc.
are used merely as labels, and are not intended to impose numerical
requirements on their objects.
[0134] The above description is intended to be illustrative, and
not restrictive. For example, the above-described examples (or one
or more aspects thereof) may be used in combination with each
other. Other embodiments can be used, such as by one of ordinary
skill in the art upon reviewing the above description. The Abstract
is provided to allow the reader to quickly ascertain the nature of
the technical disclosure. It is submitted with the understanding
that it will not be used to interpret or limit the scope or meaning
of the claims. Also, in the above Detailed Description, various
features may be grouped together to streamline the disclosure. This
should not be interpreted as intending that an unclaimed disclosed
feature is essential to any claim. Rather, inventive subject matter
may lie in less than all features of a particular disclosed
embodiment. Thus, the following claims are hereby incorporated into
the Detailed Description as examples or embodiments, with each
claim standing on its own as a separate embodiment, and it is
contemplated that such embodiments can be combined with each other
in various combinations or permutations. The scope of the invention
should be determined with reference to the appended claims, along
with the full scope of equivalents to which such claims are
entitled.
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